In general, dust adhering to the inside wall of a waste heat boiler of a non-ferrous metal smelting furnace has an adhesive property and the operation rate of the waste heat boiler is therefore decreased by spent time in removing the dust accretion from the boiler by hand lancing.
In order to remove the dust adhering to the water tube surface of the above described boiler, such apparatuses as soot blowers, hammering devices, or recirculation systems for waste gas have been used. But these apparatuses have not been sufficiently satisfactory in removing the dust accretion depending on the boiler construction or condition of concentrates to be treated.